Grinding-mill



\ YTNESSES Q///wm/ Y (No Model.)

J. '8v' B. CLARK.

` GRINDING MILL.- A

Patented Apr. 4, 1882A ggz.

'III [IIIA whim UNITED STATES PATENT OFFICE.

JOHN J. CLARK AND BYRON CLARK, OF ELGIN, ILLINOIS.

GRlNDlNG-MILL.

' SPECIFICATION forming part of Letters Patent No. 255,772, dated April 4, 1882. Application filed July 27, 1881. (Xo model) To all whom it may concern.

Be it known that we, JOHN J. CLARK and BYRON CLARK, both of Elgin, in the county ot' Kane and State of Illinois, have invented certain new and useful Improvements in Grinding-Mills; and we do hereby declare the following to be a full, clear, and exact description of the sume, reference being had to the accompanying drawings, forming part ot' this specification, in which- Figure 1 represents alongitudinal section of the mill; Fig. 2, a face view ofone of the metal grinding-rings; Fig. 3, a perspective view ot' the mill.

Similar letters ol' reference iu the several figures denote the same parts.

Our invention relates to that class of grinding-mills known as vertical mills, and it consists in certain novel improvementsin construction, whereby such mills are rendered more efficient in their operation, and which we will now proceed to describe.

In the drawings, A A', represent two burrstones, the same being of annular form and dressed on their proximate grinding-surfaces in the manner shown, or in any other suitable manner. Within each stone is Iittcd a hublike casting, B, havingau annularlateral groove or recess, b, extending nearly its entire length, and adapted to receive the body of a second hub-shaped casting, C, as shown, and to the outer portion or face ot' such casting C, is secured by bolts d d al or otherwise a metal grinding-ring, D, dressed a's shown, or in any other suitable manner. A series ot' set-screws, E, (see Figs. 1 and 3,) passing through the outer face of each of the castings B, work into and against the inner end of the casting C, and

serve to adjust the faces of the metal grinding-rin gs nearer to or farther from each other,

according to the kind, quality, and condition ofthe material to be ground, "4 The casting B of the stone A, (which latter we may here remark is the stationary stone of the mill) is mounted upon and secured to a hollow shaft, H, carrying a feed-hopper, L, while the casting B ofthe revolving stone or ruimer A, is mounted upon and secured to a solid rotary shaft, Gr, in a suitable bearing, J, and deriving motion from a belt-pulley, I, or -in any other suitable manner.

A spiral conveyer, F, projects from the end of shaft G into the hollow shaft H, and operates te feed the material to be ground from the hopper L, through the said hollow shaft in between the grinding-surfaces.

Ve have found from practical test that by the employment ot' the metal grinding-ringsin connection with thegrinding-stones full double the quantity of material can be ground in the` same time by the same power as can be ground where stones alone are used.

The set-screws E enable the metal grinders to bereadly adjusted within, flush with, or out beyond the surfaces of the stones, as occasion requires.

JOHN J. CLARK. BYRON CLARK.

Witnesses ALBERT ROGERS, D. F. DUMsEs. 

